The present invention relates to a railway freight car truck and, more particularly, to an improved railway freight car truck having lateral and vertical damping with a pedestal jaw arrangement allowing passive steering.
In a railway freight car truck, two axle wheel sets are held in a pair of laterally spaced sideframes, with a bolster extending laterally between and supported on each sideframe by spring groups. A transom is provided having ends that extend into an opening in each sideframe. The ends of the transom provide support for the spring groups. The transom ends are supported on the lower portion of the center openings of the sideframes, on transom bearings.
Two wheels are press fit on each of two axles, with the ends of the axles also fitted with a roller bearing assembly. The roller bearing assembly itself supports a bearing adapter that is fit into a pedestal jaw opening at the longitudinal end of each sideframe. A bearing adapter pad assembly is positioned between the bearing adapter and the roller bearing assembly. The bearing adapter, which is itself fit on top of the bearing assembly, is comprised of a unitary cast steel piece. The adapter pad is usually formed of a unitary elastomeric structure and is fitted on top of the bearing adapter.
The pedestal jaw and transom bearing rotate in unison about the sideframe creating lateral displacement of the transom. The lateral damper extends from the transom to the bolster. The lateral damper limits the lateral acceleration and displacement in the bolster.
Two side bearings are also typically provided on an upper surface of the bolster to assist in supporting a car bolster that is part of the structure of the freight car.
It is an object of the present invention to provide an improved railway truck having improved performance. Such improved performance is provided by vertical damping between the bolster and the sideframe and by lateral damping between the bolster and the transom. The performance is also enhanced by the rotating pedestal jaw connection to the adapter pad.